Pinpoint Test M: The Defrost System Is Inoperative - Fusion, MILAN
WARNING: This page is about a different car, the 2009 Mercury Milan, 2009 Lincoln MKZ, and 2009 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.
- M1 CHECK THE DTCs
- Refer to the results from the previous SJB self-test.
- Was DTC B1345 retrieved?
- M2 CHECK CIRCUIT CH122 (WH/OG) FOR A SHORT TO GROUND
- Key in OFF position.
- Disconnect: SJB C2280D
- Disconnect: HVAC module - EATC C228A or HVAC module - EMTC C2357A
- Measure the resistance between SJB C2280D-16, circuit CH122 (WH/OG), harness side and ground.
- Is the resistance greater than 10,000 ohms?
- YES : INSTALL a new HVAC module - EATC or HVAC module - EMTC. REFER to CLIMATE CONTROL article. REPEAT the self-test. TEST the system for normal operation.
- NO : REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
- M3 CHECK THE SJB REAR DEFROST SWITCH REQUEST PID (RDEF_SW)
- Key in ON position.
- Enter the following diagnostic mode on the diagnostic tool: DataLogger - SJB
- Monitor the SJB PID RDEF_SW while pressing the rear defrost switch.
- Does the PID value agree with the rear defrost switch when pressed?
- M4 CHECK CIRCUIT CH122 (WH/OG) FOR AN OPEN CIRCUIT
- Key in OFF position.
- Disconnect: SJB C2280D
- Disconnect: HVAC module - EATC C228A or HVAC module - EMTC C2357A
- Measure the resistance between SJB C2280D-16, circuit CH122 (WH/OG), harness side and HVAC module - EATC C228A-10 or HVAC module - EMTC C2357A-10, circuit CH122 (WH/OG), harness side.
- Is the resistance less than 5 ohms?
- YES : INSTALL a new HVAC module - EATC or HVAC module - EMTC. REFER to CLIMATE CONTROL article. TEST the system for normal operation.
- NO : REPAIR the circuit. TEST the system for normal operation.
- M5 CHECK THE SJB OUTPUT
- Disconnect: Rear Window Defrost Grid Power C402A
- Turn the rear defroster ON. Measure the voltage between rear window defrost grid power C402A-1, circuit CLS38 (VT/WH), harness side and ground.
- Is the voltage greater than 10 volts?
- M6 CHECK THE REAR WINDOW DEFROST GROUND
- Key in OFF position.
- Disconnect: Rear Window Defrost Grid Ground C402B
- Measure the resistance between rear window defrost grid ground C402B-1, circuit GD147 (BK), harness side and ground.
- Is the resistance less than 5 ohms?
- YES : REPAIR the rear window defrost grid or INSTALL a new rear window glass. REFER to Window Grid Wire Repair , Window Glass - Rear . TEST the system for normal operation.
- NO : REPAIR the circuit. TEST the system for normal operation.
- M7 CHECK FOR POWER TO THE SJB HEATED BACKLIGHT CIRCUIT
- Key in OFF position.
- Disconnect: SJB C2280A
- Measure the voltage between SJB C2280A-29, circuit SBB06 (BN/RD), harness side and ground.
- Is the voltage greater than 10 volts?
- YES : Go to M8.
- NO : VERIFY battery junction box (BJB) fuse 6 (40A) is OK. If OK, REPAIR the circuit. If not OK, REFER to SYSTEM WIRING DIAGRAMS for Fusion, or SYSTEM WIRING DIAGRAMS for Milan to identify the possible causes of the circuit short. TEST the system for normal operation.
- M8 CHECK CIRCUIT CLS38 (VT/WH) FOR AN OPEN
- Disconnect: SJB C2280E
- Key in OFF position.
- Measure the resistance between SJB C2280E-1, circuit CLS38 (VT/WH), harness side and rear window defrost grid power C402A-1, circuit CLS38 (VT/WH), harness side.
- Is the resistance less than 5 ohms?
- YES : Go to M9.
- NO : REPAIR the circuit(s). TEST the system for normal operation.
- M9 CHECK FOR CORRECT SJB OPERATION
- Disconnect all SJB connectors.
- Check for:
- corrosion.
- pushed-out pins.
- Connect all SJB connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
- YES : INSTALL a new SJB. REFER to MULTIFUNCTION ELECTRONIC MODULES article for the removal and installation procedure. TEST the system for normal operation.
- NO : The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.